The present invention relates to methods used in containing and removing leaked and spilled hydrocarbons in the marine environment.
For marine vessel fueling facilities, there is a need to remove hydrocarbons spilled or leaked on to the surface of the water as part of routine fueling operations of vessels. Spills of this nature are generated by fuel being forced out of the ventilation valve of the fuel tank of the vessel and on to the surface of the water when the fuel tank is filled to capacity. Spills also occur when fuel overflows from the fuel tank intake port of the vessel and on to the surface of the water when the fuel tank is filled to capacity during fueling operations. The task of containing these spills is necessary to prevent the hydrocarbons that are spilled or leaked on the surface of the water from spreading throughout the fueling facility area, allowing them to flow out of the containment area and polluting the adjacent waterways.
The most common method of eliminating the sheen on the water caused by these spills is to pour a dispersant such as liquid dishwashing soap on the spill. The dispersant breaks up the oily sheen into tiny particles of hydrocarbon that remain in the water and are not visible to the eye unless they are magnified. This "out of sight, out of mind" mentality is by far the most prevalent treatment of spills generated at marine fueling facilities. The use of a dispersant in this manner currently violates a number of regulations and statutes with regard to the use of dispersants in the handling of spills of this nature.
Seldom is an effort made to extract the pollutants from the surface of the water, leaving the hydrocarbons on the water to spread throughout the adjacent waterway, polluting the environment.
The prior art method of dealing with hydrocarbon spills at marine fueling facilities is extremely harmful to the marine environment immediately surrounding the fueling facility as well as posing a variety of health and safety hazards. The placement of a liquid detergent on the surface of the water to disperse the sheen does not remove the hydrocarbons from the water, it merely removes the telltale sheen from sight. The pollutants are never extracted from the water, leaving them to contaminate the area adjacent to the fueling facility. Marinelife and wildlife are effected by the pollution. The accumulation of hydrocarbons on the surface of the water renders the water unfit for drinking or swimming and presents a safety hazard. The presence of the hydrocarbon pollutants floating freely on the surface of the water creates an even greater fire hazard than that which already exists due to the handling of flammable liquids at the fueling facility. The free release of pollutants into the marine environment at marine fueling facilities poses a number of concerns that are not addressed using the present method of eliminating the sheen from the surface of the water at these facilities.
Another common approach to removing the hydrocarbon spills from the surface of the water is to use absorbent devices, typically made of a non-woven, synthetic fabric such as polypropylene, polyester or nylon. Such fabrics are petro-chemical based materials having the physical properties of absorbing liquid hydrocarbons while repelling water. These materials can be used as flat pads or sheets, rolled into long cylindrical booms or packaged in an open weave plastic net to form a sausage-like boom.
The use of absorbent devices for removing spills from the surface of the water often results in the transfer of the liquid hydrocarbon pollutants from one environment to another since the absorbent devices are subject to having the sorbed hydrocarbons released by gravity, column weight and outside forces exerting pressure on them when they are removed from the spill area. The released liquid hydrocarbons are then free to seep through the ground and enter the adjacent water column or flow downstream as waste water runoff.